As a block of wood of mass 2.0 kg slides along a floor, its speed decreases from 4.0 m/s to 1.0 m/s.
(a) How much kinetic energy does it lose?
(b) How much work does the frictional resistance of the floor do upon the block?
(c) If the reduction in speed takes place over a distance of 10 m, what is the force of friction acting on the block?